A novel method for generating 3D constructs with branched vascular networks using multi-materials bioprinting and direct surgical anastomosis

Abstract

Vessels pervade almost all body tissues, and significantly influence the pathophysiology of human body. Previous attempts to establish multi-scale vascular connection and function in 3D model tissues using bioprinting have had limited success due to the incoordination between cell-laden materials and stability of the perfusion channel. Here, we report a methodology to fabricate centimetre-scale vascularized soft tissue with high viability and accuracy using multi-materials bioprinting involving inks with low viscosity and a customized multistage-temperature-control printer. The tissue formed was perfused with branched vasculature with well-formed 3D capillary network and lumen, which would potentially supply the cellular components with sufficient nutrients in the matrix. Furthermore, the same methodology was applied for generating liver-like tissue with the objective to fabricate and mimic a mature and functional liver tissue, with increased functionality in terms of synthesis of liver specific proteins after in vitro perfusion and in vivo subperitoneal transplantation in mice. Moreover, to establish immediate blood perfusion, an elastic layer was printed wrapping sacrificial ink to support the direct surgical anastomosis of the carotid artery to the jugular vein. Our findings highlight the support extended by vasculature network in soft hydrogels which helps to sustain the thick and dense cellularization in engineered tissues.

Applications of a novel reciprocating positive displacement pump in the simulation of pulsatile arterial blood flow

“…The reciprocating positive displacement pump is also capable of simulating fingertip and skin surface blood flow under varying physiologic and pathophysiologic scenarios. An example application within this specific vascular domain is in the bioprinting of skin grafts for burn victims, where functional vascular endothelial cells require perfusion with a peristaltic pump [ 31 ]. The use of peristaltic pumps has been compared to harmonic wave flow because of its low peak-to-peak amplitude per pulse and lack of a significant flow drop between pulsations [ 32 ].…”

Bio-assembling and Bioprinting for Engineering Microvessels from the Bottom Up

“…Due to the well-developed 2D inkjet printing devices, inkjet bioprinting costs the least among the existing bioprinting methods. It is capable of printing microvessels with outer diameter smaller than 300 mm[ 80 , 81 ]. According to the working mechanism of the inkjet, the inkjet bioprinting can be divided into two types categorized by the use of either the piezoelectric actuator or the thermal actuator.…”

Applications of a Novel Reciprocating Positive Displacement Pump in the Simulation of Pulsatile Arterial Blood Flow

“…The reciprocating positive displacement pump is also capable of simulating fingertip and skin surface blood flow under varying physiologic and pathophysiologic scenarios. An example application within this specific vascular domain is in the bioprinting of skin grafts for burn victims, where functional vascular endothelial cells require perfusion with a peristaltic pump [26]. The use of peristaltic pumps has been compared to harmonic wave flow because of its low peak-to-peak amplitude per pulse and lack of a significant flow drop between pulsations [27].…”